Water Quality in Slovenia - Agencija RS za okolje

Preface
In recent years, people often ask about water quality. In most cases, they think of the taste, scent
and look of water we drink every day. But the answer to the question “What is the quality of water?”
is much more complex, since water quality is not just the quality of drinking water, and, moreover,
water quality cannot be described merely by the words ‘good’ or ‘bad’.
Water quality is a term used to describe the physical, chemical and biological characteristics of water,
usually in respect to its suitability for a particular purpose. Different water characteristics are essential
for different purposes. Industrial water, for example, must not be corrosive and must not contain
substances that result in the formation of residue on the appliance surface. Drinking water must not
contain any toxic substances and hazardous microorganisms. Furthermore, bathing water must not
contain microorganisms either, since they can cause numerous diseases. With the objective of water
protection, various regulations prescribing the limit values of concentrations of various substances in
water have been issued in the last thirty years in Europe, as well at a national level.
With the intent of sustainable use, prevention of deterioration, protection and the improvement
of the existing water status, reduction of hazardous substance pollution and provision of sufficient
quality surface and groundwater supplies, in 2000 the European Union adopted the Water Framework
Directive, which gives the Member States a legal and professional basis for an integrated approach to
water protection and management. The main objective of the Water Framework Directive is to achieve
a good chemical and ecological status of all waters by 2015. The Water Framework Directive does not
prescribe limit values for individual water parameters; it provides a new approach to an integrated
evaluation of both the chemical and ecological status of water. The new approach is based on the
conditions of the aquatic environment where the impact of human activity is either not present or
is insignificant. This means that, according to the requirements of the Water Framework Directive,
water quality is evaluated comprehensively and the natural status is defined as a state without
hazardous substances or other major loads, a state that supports the life of all aquatic organisms as it
would be in the case of insignificant human impact. At the same time, it provides a comparability of
methodologies and standards and thus, for the first time, comparability of the assessments of water
quality status among individual Member States.
For the evaluation of water quality, the Water Framework Directive in Article 8 requests the
introduction of surface and groundwater monitoring programmes. Monitoring and water quality
status evaluation is one of the key tasks of the Environmental Agency of the Republic of Slovenia. The
monitoring of water quality in Slovenia has a long tradition, but in 2007, it was carried out according
to the requirements of the Water Framework Directive for the first time. The first assessments of the
chemical and ecological status in accordance with the requirements of the Water Framework Directive
will, for the purpose of river basin management plans, be carried out by 2009.
The present publication is a brief overview of the water quality status in Slovenia and a trend evaluation
in relation to the situation in previous years. The assessments have been made in accordance with the
currently applicable regulations that have already been partially adapted to the requirements of the
Water Framework Directive. With this publication, we wish to contribute to the understanding of the
water quality issue and to the conservation of our precious water resources for future generations.
Silvo Žlebir, Ph.D.
Director General of the Environmental Agency of the Republic of Slovenia
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